Left ventricular asynchrony and raised filling pressure predict limited exercise performance assessed by 6 minute walk test

Abstract

Background: Six minute walking test (6-MWT) may serve as a reproducible test for assessing exercise capacity in heart failure (HF) patients and can be clinically predicted. We aimed in this study to ascertain if global markers of ventricular asynchrony can predict 6MWT distance in a group of patients with HF and left ventricular (LV) ejection fraction (EF) <45%.

Methods and results: This study included 77 consecutive patients (60 ± 12 years) with stable HF. LV end-diastolic and end-systolic dimensions, shortening fraction (SF), EF, myocardial velocities, t-IVT, and Tei index were measured, as well as 6-MWT distance. Patients with limited exercise performance (≤ 300 m) had lower SF (p = 0.02) and EF (p = 0.017), longer t-IVT (p = 0.001), higher Tei index (p = 0.002) and higher E/E' ratio (p < 0.001) compared with good performance patients. In multivariate analysis, only E/E' ratio [0.800 (0.665-0.961), p = 0.017], and t-IVT [0.769 (0.619-0.955), p = 0.018] independently predicted poor exercise performance.

Conclusions: In heart failure patients, the higher the filling pressures and the more asynchronous the left ventricle, the poorer is the patient's exercise capacity. These findings highlight specific LV functional disturbances that should be targeted for better optimization of medical and/or electrical therapy.